[rgmanager] Fix fuser parsing on later versions of psmisc
    
    Description of problem:
    
    fuser from rhel5 has different output respect the one from rhel4 so fs.sh needs
    a little change.
    
    Looks like the 2 differences are:
    
    *) mountpoint has an ending colon
    *) Everything except the pid file is printed to sdterr instead of stdout
    
    Bugzilla #467686